Article compacting device

ABSTRACT

An apparatus for the compaction of articles, e.g., disposable metal cans or disposable plastic bottles, includes a pair of mutually counter-rotatable, interacting squeeze rollers, wherein the first roller has a fixed support and wherein the second roller is supported in an arm-spring assembly, thereby enabling the space between the rollers to be varied according to the size and compactability of the article. In addition, the apparatus has a precompactor that includes a conveyor, e.g., a belt or chain conveyor, and an elongate press plate inclined relative to the conveyor and preferably spring-loaded, to ensure that the article is gradually flattened upstream of the squeeze rollers. The squeeze roller may be provided with an incurvate middle portion and, optionally with openings having an L, U or V-shaped cross section with gripping edges in order to facilitate the feeding of the articles, such as bottles having a mouth and bottom nipple, through the compactor.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus for the compacting ofarticles e.g., disposable plastic bottles, consisting of a pair ofmutually counter-rotatable interacting squeeze rollers, wherein thefirst roller has a fixed support and wherein the second roller issupported in an arm-spring assembly, thereby enabling the space betweenthe rollers to be varied according to the size and compactability of thearticle, and wherein the apparatus in addition is provided with aprecompactor consisting of a conveyor, e.g., a belt or chain conveyor,and an elongate squeeze device inclined relative to the conveyor andpreferably spring-loaded, to ensure that the article is graduallyflattened upstream of the squeeze rollers.

An apparatus of this kind is known, for example, from Finnish Patent93175.

However, a compactor of the said type has the drawback that thecompaction becomes sufficient. When using a compactor apparatus of thiskind in connection with a reverse vending machine for cans and/orbottles, it is essential that the articles are flattened and remainpermanently flat, as this is necessary in order to be able to transporta large number of returned goods of this kind in an inexpensive manner.When compacting, e.g., plastic bottles, the bottle neck and any screwcap attached thereto, and the concave bottom nipple of the bottle will,often cause compaction problems.

OBJECTS AND SUMMARY OF THE INVENTION

The object of the invention is therefore to provide a special squeezeroller device, and a precompactor for articles, e.g., disposable metalcans or disposable plastic bottles which are to be compacted, andwherein the precompactor feeds the articles to a subsequent finalcompactor.

The object of the present invention is therefore to overcome thedrawbacks associated with the prior art and to provide a solution whichprovides a best possible compaction.

According to the invention, the aforementioned apparatus ischaracterised in that the rollers have an incurvate middle portion so asto provide a virtually clear passageway for the mouth and bottom nippleof the article. This allows a best possible total compaction of thearticle to be obtained.

In an alternative embodiment, the apparatus is characterised in thatthere is cut out in the surface of the rollers at least one opening orrecess having an L, U or V-shaped cross-section and having a grippingedge, so that the gripping edges on opposing rollers directly interact,and upon their rotation as a pair will abut, the interacting grippingedges having the same radial distance from the rotation axis of therespective roller, and in that on such interaction the depressions inthe rollers form a space therebetween. This is of importance if thearticle, e.g., enters askew as it moves towards the squeeze rollers orhas elements which otherwise will not easily pass the rollers.

Additional embodiments of the apparatus will be apparent from thefollowing description with reference to the attached drawings, and fromthe attached patent claims.

DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail with reference to theattached drawings.

FIG. 1 is a schematic outline of the principle of the compactorapparatus according to the invention.

FIG. 2 is an elevational view of a first embodiment of the squeezerollers of the compactor apparatus, preferably for the compression ofdisposable metal cans.

FIG. 3 shows a second embodiment of the squeeze rollers of the compactorapparatus, preferably for the compaction of disposable plastic bottles.

FIG. 4 shows as a modification of the first embodiment, and in aperspective view, a third embodiment of squeeze rollers mounted on anarm-spring assembly.

FIG. 5 shows as a modification of the second embodiment, and in aperspective view, a fourth embodiment of squeeze rollers mounted on anarm-spring assembly.

FIG. 6 is a perspective view of the compactor apparatus used with theassembly shown in FIG. 4, and having a side plate removed for clarity.

FIG. 7 is a perspective view of the compactor apparatus used with theassembly shown in FIG. 5, and having a side plate removed for clarity.

FIG. 8 shows in perspective the compactor apparatus seen from theopposite side.

FIG. 9 shows a modification of the compactor apparatus.

FIG. 10 shows a further modification of the compactor apparatus.

DETAILED DESCRIPTION OF THE INVENTION

The compactor apparatus consists of a precompactor 1 and a finalcompactor 2. Under normal conditions the precompactor 1 will, whilstpre-compacting articles in the form of metal cans, e.g., of aluminumand/or steel, forcibly feed the articles into the final compactor 2, sothat the articles can easily be gripped by the rollers 2′, 2″ of thefinal compactor. It is therefore a prerequisite that the precompactor 1carries out an effective precompacting per se so that it is sufficientlyfeasible for the rollers 2′, 2″ to carry out a final compaction. This isparticularly important in the event of substantially horizontalinsertion into and passage through the precompactor. To accomplish theaforementioned compaction, it is essential that both the precompactor 1and the rollers 2′, 2″ are able to adjust to and maintain a virtuallyconstant force of compaction on articles of a normal compactable type.In the proposed embodiment, which does not define the limits of theinvention, the precompactor 1 which functions simultaneously as aforward feeder, may consist of a belt or chain conveyor 1′ and a squeezedevice 1″, e.g., a press plate or conveyor, e.g., of the belt or chaintype, disposed at an angle α relative thereto.

The angle α between the two main parts 1′, 1″ of the precompactor ispreferably in the range of 15° to 45°. An especially preferred angle maybe about 20°. In the further discussion of the compactor apparatus,e.g., in connection also with FIGS. 6-10, part 1′ of the precompactor 1is in the form of an inclined press plate. However, this design shouldnot be seen in any way as defining the limits of the invention. Thelower roller 2″ is fixedly supported and the upper roller 2′ issupported in a highly schematically indicated arm-spring assembly 3which will be described in more detail in connection with theembodiments that can be seen in FIGS. 4-10. The squeeze device 1″ willturn about a centre of rotation 1″ and preferably be spring-loaded bymeans of a spring mounting 4.

The squeeze device 1″ may conceivably be mechanically connected to thearm-spring assembly 3 of the roller 2′, so that the rotational motion ofthe squeeze device 1″ will actuate the motion of the assembly 3, andthus also the rotation of the roller 2′. In a solution of this kind thespring mounting may be omitted.

When there is a separate springing as indicated in FIG. 1, thearm-spring assembly 3 of the final compactor and thus the motion of theroller 2′ relative to the roller 2″ may be completely independent of oneanother.

Another solution is to use separate springing for the precompactor 1 andthe final compactor 2, but to include a mechanical coupling 5, 5′ asindicated schematically, so that the squeeze device 1″ will only causerotational motion of the arm-spring assembly 3 of the final compactorand thus a space between the rollers 2′, 2″ when the downstream end ofthe squeeze device moves upwards more than a predetermined distance.Normally the space between the rollers should be as small as possible sothat best possible final compaction is obtained.

To ensure a good forcible forward feed of articles, the conveyor 1′ ispreferably provided with gripping means 1″″, such as, e.g., spikes,barbs, friction facing or the like.

The squeeze rollers according to FIG. 2 consist of two counter-rotatingrollers 6, 7. The rollers may optionally be provided with afriction-generating surface, e.g., in the form of serrations 8, 9, toimprove the gripping power of the rollers. The rollers 6, 7 areespecially designed for the compaction of articles such as disposablemetal cans. Initially, the rollers 6, 7 are rotatably supported onrespective mounts 10, 11 and 12, 13.

In the event that it is desirable to compress articles such as, e.g.,disposable plastic bottles, it will be necessary to design the squeezerollers somewhat differently. In this connection, reference will be madeto FIG. 3 which shows two counter-rotating rollers 14, 15. The rollersmay be provided with an optional friction-generating surface, e.g.,formed by means of serrations 16, 17 in order to improve the grippingpower of the rollers. The squeeze rollers 14, 15 have a respectiverecessed portion 18, 19 in the middle thereof in order to provide avirtually clear passageway 20 for the mouth and bottom nipples of thebottles, whilst the portions at the sides of the recessed portion 18, 19have a very small clearance. Squeezing the lateral edges of thearticles, in this case, e.g., bottles, completely flat, will result in apermanent deformation in the bend that occurs and thus the article willremain permanently flat, apart from the area around the mouth and thebottom nipple.

Ideally, the rollers 14, 15 are rotatably supported in respective mounts21, 22 and 23, 24.

Just as the aim in the case of cans is to obtain a maximum axial motiontowards the final compactor 2, so it will of course also be important toaim to guide the bottle mouth and bottom nipple towards the recessedportions 18, 19 of the rollers 14, 15 which together form the passageway20, so as to allow the mouth and bottom nipple to pass through the finalcompactor without causing any particular problems. This can be effectedby there being an appropriate distance between the side walls 25, 26 ofthe precompactor, see FIG. 8. It must also be noted that as soon as thegripping means 1″″ on the conveyor 1′ grip the bottle, the onwarddirection of the forcible feed and direction towards the ring-shapedpassageway 20 formed between the rollers will be determined. A correctinsertion at the upstream end of the precompactor 1 is thus essential.The mouth and bottom nipple of the bottle can thus easily be guidedactively towards the recessed portions 18, 19 and the passageway 20.

If a can enters the precompactor askew or perhaps is not sufficientlyprecompacted, the rollers 6, 7 will not be able to grip the can properlyand compress it further. To avoid precisely this problem, there isprovided in each roller, indicated in FIG. 4 by the reference numerals6′, 7′, at least one respective depression or opening 27 and 28 havingis gripping edge 27′ and 28′ . As can be seen from FIG. 4, the grippingedges 27′, 28′have same radial distance from rotation axis of therespective roller 6′, 7′. Further, the innermost edges 27″, 28″ of therollers 6′, 7′ have also a same radial distance from rotation axis ofthe rollers. The openings preferably have an L, U or V-shapedcross-section and extends across the entire width of the rollers 6′, 7′.Since the rollers 6′, 7′are made to turn synchronously via gearing 29,30, the said gripping edges 27′ and 28′will in a pincher movement grip apart of the can which is unable to enter the gap between the rollers.This may result in the can either being swept along through the spacebetween the rollers in the final compactor or being gripped bit by bitand pulled through. The space formed between the openings 27, 28 willnormally be large enough to take, e.g., non-precompacted parts of or onthe can. Of course, it will be possible to arrange several openings ofthis kind across the rollers along the periphery thereof, but normallyat least one opening of this kind per roller will be advantageous andsufficient.

If a bottle enters the precompactor somewhat askew, so that the mouthand/or bottom nipple of the bottle does not encounter the passageway 20,there is for this purpose provided in the surface of each roller 14′,15′, as indicated in FIG. 5, on each side of the respective recessedportion 18, 19 thereof, at least one opening 31, 32 and 33, 34 in therollers 14,′, 15′ having gripping edges 31′, 32′ and 33′, 34′. As can beseen from FIG. 5, the gripping edges 31′, 33′ and 32′, 34′ have sameradial distance from rotation axis of respective roller 14′, 15′.Further, the innermost edges 31 ″, 33″ and 32″, 34″ also have a sameradial distance from the rotation axis of the rollers. The openingspreferably have an L, U or V-shaped cross-section and extend across theentire width of the rollers 14′, 15′, i.e., on each side of therespective recessed part 18, 19. Since the rollers 14′, 15′ havesynchronised rotation via the gearing 29, 30, the said gripping edges31′, 32′, 33′ and 34′ will in a pincher movement grip a bottle part,e.g., the mouth or bottom nipple which has not come into the gap betweenthe rollers or through the passageway 20 and will either carry thebottle through the final compactor or grip the bottle bit by bit andpull it through. The space formed between the depressions or openings31, 32 and 33, 34 will normally be large enough to take a bottle mouthor bottom nipple. Of course, it will be possible to provide severaltransverse openings 31-34 along the periphery of the rollers, butnormally at least one such opening on each roller will be regarded asadvantageous and sufficient

The invention will now be described with reference to FIGS. 6 and 7, butdetails already described in connection with FIGS. 4 and 5 will not berepeated.

The compactor apparatus has a precompactor consisting of a belt or chainconveyor 35 (denoted by reference number 1′ in FIG. 1 and denoted byreference number 58 in FIGS. 9 and 10) and a squeeze device 36 (denotedby reference number 1″ in FIG. 1 and denoted by reference number 64 inFIGS. 9 and 10) in the form of a press plate which acts almost as aslide plate, and which is inclined relative to the conveyor 35 at anangle α, e.g., in the range of 15-45°, preferably 20°. As analternative, as indicated in connection with FIG. 1, the squeeze device36 may be in the form of a belt or chain conveyor.

As indicated in FIG. 1 for the conveyor 1′, this may be provided withgripping means 1″″, e.g., spikes, barbs or a friction facing whichensures good engagement with the article that is to be fed forciblytowards the squeeze rollers, whilst the article is precompacted. InFIGS. 6 and 7 the gripping means are indicated by means of the referencenumeral 37 (denoted by reference number 1″″ in FIG. 1).

As was the case with the previous embodiment of the compactor apparatusaccording to the invention, in this embodiment for processing plasticbottles there is also a need for mechanisms which ensure that both theprecompactor and the final compactor release at a given load caused byarticles which are not compactable, so that such articles either passthrough the compactor apparatus more or less uncompacted or areretrieved by reversing the drive mechanism of the compactor apparatus.If the articles that are inserted are not compactable, the compactorapparatus must of course be capable of handling such articles withoutthe apparatus sustaining any damage in doing so.

By avoiding flattening bottle mouths and bottom nipples, the powerrequirement is considerably reduced, and this leads to a substantialreduction in the need for mechanical strength in the apparatus and thusalso in the costs of the apparatus.

Under normal conditions, the precompactor 1 is to effect the forciblefeeding and compraction of metal cans or plastic bottles, such as PETbottles, into the squeeze rollers 6′, 7′; 14′, 15′ in such a way thatthe squeeze rollers are easily able to grip the precompacted bottle. Theprecompactor, with its two parts 35 and 36, will thus have to carry outan effective compaction in order to ensure that the compaction rollershave sufficient grip on such precompacted article.

The squeeze device 36 in the form of a press plate which forms the angleα with the conveyor 35 is rotatably supported at its upstream end in apivot 38. The lower roller 7′; 15′ is normally fixedly supported, whilstthe upper roller 6′;14′ is supported in an arm-spring assemblyconsisting of arms 39, 39′ and springs 40, 40′, e.g., gas springs. Thearms 39, 39′ are rotatably mounted about a fixed shaft 41. A crossmember 42 extends between the arms 39, 39′. At the downstream end of theprecompactor, its inside diameter will preferably correspond to theaccessible inside diameter between the squeeze rollers. The press plate36 may, in the case of the embodiment in FIG. 7, have a recess orcut-out (not shown) at the bottom and on the underside, so that thecentral part of the downstream end of the precompactor has an insidediameter corresponding to the passageway 20 between the rollers 14′,15′, whereby the mouth and bottom nipple of a bottle can more easilypass unobstructed from the precompactor towards the squeeze rollers.

The spring mounting or suspension of the press plate 36 may, e.g., maybe made using a spring device 43, e.g., rubber blocks which are fastenedin a bracket 44, thereby rendering the function of the precompactorindependent of the springs 40, 40′. However, it is conceivable inindividual cases that the lower end 36′ of the press plate 36 is pressedso far upwards by an article that it will bear against the cross member42 and thus press the free ends of the arms 39, 39′ upwards. The springs40, 40′ at their respective upper part are in engagement with arespective mounting bracket 45, 45′which is fastened to the side walls25, 26 of the precompactor. A cross member 46 mayo optionally be placedbetween the upper end of the springs to provide cross stiffening.

A motor 47 will via gearwheels 48, 49 and a toothed belt or chain 50drive the lower roller 7′; 15′ and thus the upper roller 6′; 14′ via thegearing 29, 30. Furthermore, the gearwheel 49 will drive the conveyorgearwheel 51, as indicated in FIG. 8. The motor 47 may optionally have atransmission 52 between its drive shaft and the output shaft 53 whichdrives the gearwheel 48.

Although the squeeze rollers 6′, 7′ and 14′, 15′ in FIGS. 6 and 7respectively, and in more detail in FIGS. 4 and 5, primarily aresuitable for compacting metal cans and plastic bottles respectively, itwill be appreciated that the illustrated embodiments are not limited tohandle only this form of disposable packaging, but that, e.g., boxes,cartons having a screw cap or the like also may be compressed using suchapparatus.

Under normal operational conditions, the compression forces will beconsiderably higher in connection with the final compaction than thosein effect in the precompactor. A force ratio of 10:1 might be realistic,although of course this should not be understood as defining the limitsof the invention.

By studying FIGS. 6-8, it will be understood that the spring forces fromthe springs 40, 40′ will diminish the more the free ends of the arms 39,39′ move upwards, inasmuch as the springs 40, 40′ are inclined.

If the end 36′ of the press plate 36 had been mechanically connected tothe arms 39, 39′, the compaction forces in the precompactor and thefinal compactor, i.e., with the squeeze rollers, would be greatest whenthe space between the precompactor parts 35, 36 is smallest andsimilarly when the space between the rollers 6′, 7′; 14′, 15′, issmallest and the forces would decrease with the widening of thesespaces. When the arms 39, 39′ turn relative to the shaft 41, the torquefor the closing force (the springs 40, 40′) will be reduced at the sametime as the torque for the opening force (caused by the article)increases. For instance, a high compaction force in connection with therollers 14′, 15′ during normal operation, i.e., a small space betweenthe rollers, is necessary to provide a permanent deformation of thelateral edges of the bottles.

The embodiment in FIGS. 9 and 10 will now be described in more detail.In both embodiments a common spring mounting is proposed for theprecompactor and the compactor using inclined springs 53 fastened in theside wall of the precompactor by means of a fixing bracket 54. Operationof the apparatus can be effected by a rotary motor, indicatedschematically by reference numeral 55, which preferably drives the lowerroller 56. The conveyor 58 is driven via a chain or belt connection 57,the conveyor 58 belt or chain being moved over respective rotating endrollers 59, 60. The rotation of the lower roller also causes operationof the upper roller 63 via a gear transmission 61, 62.

The compaction plate in FIGS. 9 and 10 is indicated by reference numeral64 and at its upstream end is rotatably mounted in a journal 65. Ifnon-compressible articles are inserted, the precompactor plate 64 willbe lifted at its downstream edge 64′ and thus also lift the front edgeof the arms 66 about the shaft 67, so that an article of this kindpasses unobstructed through the final compactor. In order to provide anecessary spring loading on the arms 66, gas springs 53 mayadvantageously be used as springs. Other types of counter-force devicesare also conceivable. The compaction forces which are caused by theprecompactor and by the rollers 1, 2 will thus be limited by the forcesexerted by the springs 53, and under normal conditions could be, e.g.,ten times greater for the compression rollers 1, 2 than for theprecompactor 17.

In FIG. 10 the motor 55 will drive the lower roller 56 and via chain 57drive the precompactor conveyor 58. The lower roller also drives theupper roller via a drive chain 68 and gearwheels 69, 70 and 71.

In a compactor apparatus of this kind, there will also be a need fortechnical solutions which ensure that both the precompactor and therollers are released by a given load caused by articles which are notcompactible, and that these can pass through the compactor apparatusmore or less uncompressed.

From the system for power transmission between the upper roller 6′; 14′and the lower roller 7′; 15′ via gearing 29, 30 it will be understoodthat the rollers can be moved slightly apart without the gear engagementceasing. However, if the article that is to pass through the compactorapparatus is too large or of a non-compressible type, the gearwheelengagement will be released, whereby the upper roller 8 will no longerrotate by force via the gearwheels 29, 30. It will normally be desirableto allow the movement of the arms 39, 39′ to be limited so that thegripping function of the rollers is maintained, at the same time as thegearwheel engagement is kept up. This means that the gearwheels 29, 30should have large (long) teeth, so that the engagement is maintainedeven if the gearwheels travel some distance apart.

However, if the apparatus is so adapted that the gearwheels disengagefrom each other the gearwheel engagement will function again as soon asan excessively large article of this kind has passed out of thecompactor apparatus.

If an article enters the precompactor and is of such a type that itcannot possibly pass between the rollers 8, 9, a detector 72 can bepositioned so that it stops the apparatus drive motor 47; 55 if thepress plate passes the detector. Thus, an alarm can be given to indicatethat the manual removal of such an article is required. Alternatively,the motor can be made to turn in the opposite direction on suchdetection so that the article is fed back to the point of insertion. Asan alternative to the use of the motion detector 72, a speed monitor(not illustrated), of a type that is known per se, may be used whichmonitors the drive speed of the motor and causes the motor to stop orrotate in the opposite direction if the drive speed falls below adetermined threshold. As yet another alternative (not illustrated), thepower consumption of the motor can be monitored and the motor made tostop or reverse if the power rises above a certain threshold or thepower increase per time unit passes a threshold.

What is claimed is:
 1. An apparatus for compacting disposable plasticbottles, comprising a pair of mutually counter-rotatable, interactingsqueeze rollers, a precompactor including a conveyor and an elongatedsqueeze device inclined relative to the conveyor so that the article isgradually flattened upstream of the pair of mutually counter rotatableinteracting squeeze rollers and wherein a first said squeeze roller hasa fixed support and wherein a second said squeeze roller is supported inan arm-spring assembly, thereby enabling a space between the first andsecond squeeze rollers to be varied according to the size andcompactability of the bottle and wherein the first and second squeezerollers each have an incurvate portion for providing a virtually freepassageway for a mouth and a bottom nipple of the bottle.
 2. Anapparatus as disclosed in claim 1, characterized in that the squeezeroller arm spring assembly is adapted to move independent of adownstream portion of the squeeze device.
 3. An apparatus as disclosedin claim 1, wherein a spring mounting in the spring roller arm springassembly is mechanically separate and independent of a spring mountingin the squeeze roller device.
 4. An apparatus for compacting disposableplastic bottles, comprising a pair of mutually counter-rotatable,interacting squeeze rollers, wherein a first said squeeze roller has afixed support and wherein a second said squeeze roller is supported inan arm-spring assembly, thereby enabling a space between the first andsecond squeeze rollers to be varied according to the size andcompactability of the bottle, and wherein the first and second squeezerollers each have an incurvate portion for providing a virtually freepassageway for a mouth and a bottom nipple of the bottle.
 5. Anapparatus as disclosed in claim 4, wherein the incurvate portion islocated midway between the roller ends.
 6. An apparatus as disclosed inclaim 1, wherein a gear drive of the second roller is disengaged whensaid space exceeds a limit caused by a too large or non-compressiblebottle entering said space.
 7. An apparatus as disclosed in claim 4,wherein a gear drive of the second roller is disengaged when said spaceexceeds a limit caused by a too large or non-compressible bottleentering said space.
 8. An apparatus for compacting disposable plasticbottles, comprising a pair of mutually counter-rotatable, interactingsqueeze rollers, each said squeeze roller having an axis of rotation,wherein a first said squeeze roller has a fixed support and wherein asecond said squeeze roller is supported in an arm-spring assembly,thereby enabling a space between the first and second squeeze rollers tobe varied according to the size and compactability of the bottle, andwherein the first and second squeeze rollers each have an incurvateportion, each said incurvate portion extending along a circular patharound the axis of rotation of each said squeeze roller, said incurvateportions being proximately tangent to define a virtually free passagewayfor a mouth and a bottom nipple of the bottle at the area of proximatetangency.